Scott made me do it.

[Alexander Cherepanov]

Hi Andrew!
On Fri, 21 Aug 2009 21:22:00 -0400, Andrew Lewman <andrew at torproject.org> wrote:

>>> Sorry my ignorance but why caching proxy is better than built-in 
>>> Firefox cache?
>> 
>> Enabling torbutton disables firefox cache.  I didn't test non-tor
>> firefox caching.

> Thinking about this some more, torbutton doesn't disable Firefox memory
> caching.

I've just checked Torbutton doc and the situation turns out to be more 
intricate. There is an option in Torbutton which turns memory cache 
off (extensions.torbutton.block_cache, see
https://www.torproject.org/torbutton/design/#id2998213 ). The reason 
is probably to avoid tracking via stored unique identifiers (item 5 in 
https://www.torproject.org/torbutton/design/#attacks ). So the 
question is whether caching is acceptable from anonymity POV.

When using the cache in Firefox the issue could be mitigated by 
SafeCache plugin. External caches are harder to defend (maybe checking 
referer could help?).

Alexander Cherepanov